#include <stdio.h>

int main(int argc, const char *argv[])
{
	char buff[128] = {0};
	gets(buff);
	
	int i = 0;
	while(buff[i]){
		i++;
	}
	// 上面循环结束时 i 是 '\0' 的下标
	i--; // 让i作为做后一个字符的下标
	int j = 0;
	char temp = 0;
	while(j < i){
		temp = buff[i];
		buff[i] = buff[j];
		buff[j] = temp;
		i--;
		j++;
	}
	printf("%s\n", buff);

	return 0;
}
